Honing mandrel



Dec. 5, 1950 J, QUNNEN 2,532,682

HONING MANDREL Filed Feb. 15, 1949 ATTORNEY Patented Dec. 5, 1950 V UNITED STATES PAT ENT F Fl C E- 2,532,682 n-ON ING manna roseprr Simnen, Cfay'tb'n, Mo. Application February 15, 1M9; Serial No; 76,591

, invention relates to ma'ndrels. to be used in honing machines of' the general type shown in my'prior patent No. 2,377,588,. patented. une 5, 1945, and comprehends a structure particularly adaptable to honest for finishing, the interior of relatively small bor es'. Heret'ofore it has been custmnar'y in". the" finishing of small bores to use a mandrel carrying a single honing surface as shown for instance in my prior patent nu 2;376j851. However, it is now proposedby means or a novel structureto provide a bone carrying mandrelfor use" the finishing of small boresin which a multiplicity of bones may be utilized; suitably spaced and arranged; and so assembled as to retainasubstantially rigid assembly;

One of the objects of theprese'nt invention is to construct a mandrel in which a multiplicity of diametrically arranged homes' are provided for simultaneous adjustment by means 01" an axially movable wedge;

Another object of the" inventiontoprovide in amandrelofthe type described astructure having'the characteristics of a substantially solid body, whenthe bones and wedges are-assembled:

A furthen object of the invention is" to pro'-' vide a mandrel structure inwhich there is provided an axial bore for the arrangement and movement of an adjusting wedge; thebore errtending throughout the length of the relatively small cylindrical mandrel= bodyand cooperating with wedges arranged in atransversewedgeslot which: intersects the axial-bore with" its central p'lane at the-axi's of the bore; so" that the-bones tl'iemselve's can be placed" in I pockets in' the*man-' drel body' at each sideof the wedge to'be-solidly' a-nd compactly held therein during all positions of adjustment and operation of the device;

Further" features 0f-the invention; such as the structure permitting maximum adjustment for the-size-of the-mandrel, without interfering with the strength and rigidity-pf the assembly; will appear from an' inspection of the accompanying claims and drawings, in which latter similar ref er'ence characters designate corresponding parts throughout the several views, in wliich:

Fig:- 1; is alongitudinal-vertical section=through a; mandrel,. showing the stones and wedges in retractedpositiong;

Fig, 2-.-is a: longitudinal" horizontal sectiom of: the disclosure.- of Fig. 1:;

Fig.- 3visa transverse section taken on line 3-3 ofFigvlq.

Eig. 4 is a side elevation; and v Fig. 5 i's; an. exploded. View showing the wedge and the-hones- The mandrel is conventionally constructed of twoparts, the: first being the chuck head indicated: by reference character l, this; chuck head being. formed: with astepped bore 2, 2 and 2 for receiving the operating end of the wedge bar 3 and partof the machine operating mechanism. The chuck head i is formedwith a lateral. slot 4 communicatingwiththe bore and in which the relatively wideterminal 5 ofthe wedge bar 3 is arranged and adapted to travel during the adjustment ofthe' hones. The terminal end 5- ofthe wedge bar 3' is tor-med with a. hooked end portion 6' for engagement. with an actuating mechanism of a honing machine as is conventional in such instances. The. hooked terminal portion 5 ofthe wedgebar 3 is shownas formed of a separate piece of material which: is welded or otherwise securedto'the'inner end of the elongated wedge bar body 31, thisstructure being mainly for the purpose of: convenience in manufacture and to reduce the costs;

The: elongated mandrel body 8 is constructed of av steel rod' which has been provided with: a rectangularaxial bore 9 inwhich the elongated wedge: bar 3- i's; normally arranged, the. wedge bar Sabeingiof dimensions to snugly engage thewalls 0t the rectangular: bore Sgthetolerances between thepartsbeing ample to permit manipulation of the wedge bar 3 but" preventing lateral or vertical= shiftinglr m-ovementwhen: the device is in use.- The cylindrical; body- 8 projects into the outer: reducedbore Z'b'of the headl and is fixed thereinbyany suitable" and expedient means. By forming the head I and the; mandrel body 8 of? separate material it will. be'ap'parentv to one skilled in the art that a substantial? amount of machining and; materialv can be; saved in producing the structure in question.

The bore 9; which is generally of" rectangular cross-section is of constant area throughout its entire lengthami extends from-within the inner chamberof the-head I as defined bythe bore 2 throughout the cylindrical bodyr8; Adjacent the outer end.- ofithe mandrel: body: 8: a transverse elongated slot of rectangular form is provided, this slot intersecting the bore 9 and being of substantially greater width than the bore 9 and having its longitudinal side walls It) offset a substantial distance at each side of the walls of slot 9 so as to provide a recess at each side of the wedge bar bore 9 for the reception of hone carriers l2. The transverse slot has its longitudinal center lying in a common plane with the longitudinal center of the bore 9 so that the hone carrying recesses defined by the walls H] and 1| are of equal size, of rectangular form, and are defined by the longitudinal walls Hi, the end walls and when the wedge bar 3 is in position the inner walls of these hone carrier recesses are defined by the side faces of the wedge bar 3. The transverse dimensions of the hone carrier recesses defined by the walls II) and H at each side of the mandrel bore 9 are such as to permit the vertical wall portions l2 of the hone carriers to be seated therein, the inner surfaces M of the vertical walls I2 of the hone carriers lying flush with the side walls of the wedge bar 3 when the latter is in position, and the outer faces of the hone carriers continuously contact and lie flush with the elongated walls II! of the hone carrier recesses, with the end wall portions of the vertical walls of the hone carriers abutting the end walls ll of the recesses, the fit in each direction being sufliciently accurate as to prevent any shifting of the parts other than in a direction transverse to the movement of the wedge bar 3 when the latter is shifted to secure necessary adjustment of the hones carried by the hone carriers.

In order to operate the hone carriers by means of the wedge bar 3 it will be seen from an inspection of Fig. 5 that the wedge bar 3 is formed at its opposite faces and at its outer ends with the slots I5, the slots at each side being arranged at opposed angles to engage and operate the pair of hone carriers which have similarly arranged ribs 56 projecting from the inner faces of the vertical walls id for cooperation with the slots IS.

The peripheral surface of the barrel 8 of the hone body inward of the hone slots is formed at each side with a multiplicity of diagonal parallel slots I8, the groups of slots at each side are all of substantially the same width and depth, the bottom faces i9 being flat and the side walls 29 defining the slots extending vertically with respect to the bottoms thereof. These slots which are provided for the discharge of a coolant may be formed in any suitable manner as by the use of a metal saw, milling machine, or the like. In the illustration shown, the diagonal passages for the coolant are arranged at an angle to the axis of the body and in parallel relation, the groups of slots in each instance traversing approximately one quarter of the circumferential surface of the hone barrel and originating in each instance at a line extending longitudinally of the barrel at approximately the longitudinal center of the hone slot. This arrangement facilitates the movement of the coolant and its discharge from the bore which is being operated upon by the hone assembly.

The individual hone carriers include the vertical elongated wall portions [2 and the horizontal hone carrying flanges 2|, the inner faces of the walls l2 and the flanges 2| being at right angles to enable the flange portion 2| to overlie and continuously engage and seat the marginal edge 22 of the wedge bar 3. Obviously the lateral flange 2| of one hone carrier will seat upon the one edge portion of the wedge bar 3, while the corresponding flange of the other hone carrier will seat upon the opposite edge of the wedge bar. The edges 22 of the wedge bar in each instance lie at right angles to the side walls thereof, thus insuring the proper seating of the faces 2| of the hones. The outer surfaces of the lateral flanges 2| of the hones are machined to present two faces lying at similar acute angles with respect to the inner face of the flange and have secured thereto by an adhesive or otherwise the hone elements 23, the outer faces of which initially may be flat but will normally constitute substantially a continuation of the circumferential surface of the tubular mandrel body as shown in Fig. 3. By this means a maximum honing area will be presented to the work and this working area will properly distribute the inherent forces created as a result of the honing operation due to the frictional engagement between the hones 23 and the wall of the bore against which it may be operating. It will be further noted by an inspection of Fig. 3 that the thickness of the wedge bar 3 and the thickness of the vertical walls l2 of the two hone carriers constitute a measurement, with suitable tolerances for adjustment, corresponding to the distance between the transverse walls of the hone slot it) so that in assembly these parts are prevented from having play in any direction, but on the contrary present substantially a solid working element for accomplishing the desired finishing operation in a bore. The solid structure provided by the assembly eliminates chattering and consequently marring of the surfaces being finished. Also the transverse arrangement of the hones with respect to the associated parts provides the required passageways for the movement of a coolant to all of the area being honed, thus insuring against undesirable heating.

I claim:

1. In a honing mandrel for use in finishing small bores in metal structures, a body including an enlarged, hollow head portion, a relatively slender mandrel shaft extending concentrically from said body, said shaft being formed throughout with a straight uniform axial bore of rectangular cross section, a relatively wide transverse hone carrier slot extending through the outer end portion of the shaft, and intersecting said bore, the width of the slot being such as to provide lateral hone carrier receiving recesses at each side of said axial bore, an elongated wedge bar of rectangular cross section snugly arranged V in said bore for longitudinal movement, said wedge bar being formed with parallel angularly extending wedge slots at each side, and hone carrie elements having portions snugly seating in said recesses and constructed and arranged for radial movement therein, said hone carriers being formed with parallel angularly arranged wedge projections normally extending into the wedge slots of said wedge bars, and including angular hone carrying portions overlying the edge portions of said wedge bar.

2. The substance of claim 1 characterized in that the inner faces of the hone carriers are in a common plane with the side faces of the bore and abut the side faces of the wedge bar.

3. The substance of claim '1 characterized in that the hone carrying elements are positioned for radial adjustment in the hone recesses by the side walls of the wedge bar which forms the inner guide for the hone, and include hone supporting projections which overlie the opposite sides of the wedge bar.

4. In a hone mandrel, a mandrel shaft having a longitudinal axial bore formed with parallel, spaced walls, a slot extending transversely through the bar and intersecting said bore to provide hone carrier recesses ofiset laterally from said axial bore, a wedge bar of uniform cross section extending through the mandrel bore and lying flush against the parallel walls thereof, said wedge bar having at each side thereof angularly disposed slots, and hone carriers in said hone slots at each side of the bar having portions engaging said slots, said carriers being of L-form and the leg of each carrier having its inner face overlying the edges of the wedge bar, and supporting elongated radially extending hone ele ments.

JOSEPH SUNNEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED sTATEs PATENTS 10 Number Name Date 2,256,495 Rioux Sept. 23, 1941 2,302,207 Gjertsen Nov. 1'7, 1942 2,336,043 Staples Dec. '7, 1943 2,350,969 Sunnen June 6, 1944 2,376,851 Sunnen May 22, 1945 2,419,660 Satterthwaite Apr. 29, 1947 

